1. Field of the Invention
The invention relates to a pneumatic exercise foot pad device, and more particularly to a pneumatic exercise foot pad device with operational adjustability.
2. Description of the Related Art
FIG. 1 shows a conventional pneumatic exercise foot pad device 100 that includes a pair of pads 11 and a pair of tubes 12 that are formed integrally with the pads 11. When a user treads on the pads 11 by alternately treading one pad 11 up and the other pad 11 down using his two feet, air in the pads 11 flows through the tubes 12 to drive deformation of the pads 11. In this manner, the muscular strength of the feet or legs can be enhanced.
However, since the resistance blocking air flow through the tubes 12 cannot be adjusted, the resistance against the two feet also cannot be adjusted. Hence, the pneumatic exercise foot pad device 100 has the disadvantages of a monotonic process and poor operational variation. Moreover, because the tubes 12 are disposed only in the front and rear positions of the pads 11, when one foot presses downward, the central portion of the foot pad 11 on which this foot treads protrudes rather than keeping an even overall upper surface. If the user cannot adjust his body balance or center of gravity to accommodate the protruding center portion of the pad 11, he may become unbalanced and may fall. Hence, it is not safe to use the pneumatic exercise foot pad device 100.
FIG. 2 shows another conventional pneumatic exercise foot pad device 120 that includes a pair of pads 13, a tube 14 connecting the pads 13, and a valve 15 attached to the pads 13. The pads 13 and the tube 14 are integrally formed, whereas the valve 15 is attached thereto thereafter. When a user steps on the pads 13, by operating the valve 15, the resistance blocking air flow through the valve 15 can be adjusted to change the treading force on the corresponding treading area.
However, because the valve 15 is not integrally formed with the pads 13, after a period of use, the seal between the pads 13 and the valve 15 may allow air to escape. Furthermore, because only a partial area is used for air flow adjustment, it is difficult to control the resistance forces at the front and rear portions of the pads 13. Moreover, the pneumatic exercise foot pad device 120 still has the disadvantage of not evenly raising the upper surface of the pads 13.
FIG. 3 shows a stepper to exercise the muscular strength of the feet. The stepper has multiple disadvantages. For example, the tread pad is too rigid making the stepper uncomfortable to use. In addition, the stepper has monotonic process and poor operational variation, and is unable to train a user's balance sense.